Bore hole survey device



June 6, 1933. w, E. GILBERT BORE HOLE SURVEY DEVICE 4 Sheets-Sheet lFiled Aug. 8, 1927 fTTGP/VEL/ June 6, 1933.

W. E. GILBERT BORE HOLE SURVEY DEVICE Filed Aug. 8, 1927 4 Sheets-Sheet2 Jun 6, 1933. w E, G|| BERT 1,912,768

BORE HOLE SURVEY DEVICE Filed Aug. 8, 1927 4 Sheets-Sheet 3 Egla'.....

f5 ffofA/fj/ June 6, 1933. W. El GlLBERT 1,912,768

BORE HOLE SURVEY DEVICE Filed Aug. 8, 1927 4 Sheets-Shet 4 Patented June6, 1933 UNITED STATES PATENT oFElcE WAL'ION E. GILBERT, OF PASADENA,CALIFORNIA, ASSIGNOR TO SHELL OIL COMPANY,

OF SAN FRANCISCO, CALIFORNIA,

A COR:POIRA'IION` OF CALIFORNIA BRE HOLE SURVEY DEVICE Application filedAugust 8, 1927. Serial No. 211,409.

As is well known to those familiar with petroleum exploration, it isimpossible with existing equipment to drill a bore hole which doves notdeviate from the vertical. These deviations, or angular changes in thecourse of the bore hole, are due in some instances to the side-trackingof tools or pipe lost in the hole, and are presumably vdue in' otherinstances to bending of the drilling stem within the hole, and to thelack of homogeneity of the material penetrated.' It will thus be seenthat the depth to which it will be necessary to drill, and thepossibility of completing a producing well, in a restricted oilproducing arca, can often be gauged by an accurate survey of the courseof the bore hole. Such a survey is also essential to an intelligentstudy of underground strata as indicated by core samples. The purpose ofthe present inventi on is to provide a borehole surveying instru-4 mentwhich will record the direction and amount of inclination of a well, andwhich is of improved accuracy and simplicity, and

'sufficiently rugged to withstand the high pressures and temperaturesencountered in American drilling practice.

An important element of any bore hole surveying instrument is the meansemployed to maintain a lixed azimuth or direction at the instrument,from which the direction of inclination of the bore hole is measuredlAfter careful consideration in the light of actual tests,l the compasshas been eliminated asunreliable for this purpose due to the existencel. in many cases of local attractions which cannot be satisfactorilycompensated for in the material surrounding the bore hole. The method oflowering the instrument at theend of a string of pipe which is kept fromturning at the surface, has also been eliminated since there is no knownmethod of preventing the lower end of the string of pipe from twistingunder1 the interaction of internal stresses in the pipe with the loaddue to its own weight, and superimposed bending stresses due to thepipes conforming to angular deflections of the bore hole. For thesereasons the gyroscope has been selected as the only thoroughlydependable means of maintaining' a ixed direction within the instrument,and

is thus shown in the preferred form of this invention.

It is an object of my invention to provide a bore hole survey device inwhich the recording apparatus has a fixed azimuth.

It is a further object of the invention to provide a bore hole surveydevice in which the amount and direction of inclination of the bore holeat a particular point is recorded by reflected light rays.

My invention comprehends the use of a pendulum which has a fixedazimuth, the azimuth being fixed by use of a suitable means such as agyroscope. This pendulum includes a source of light and includes mirrorsfor reflecting the light rays outward onto a film. The light rays form arecord on the film each time the light source is illuminated.

`It is an object of this invention to provide a bore hole survey devicein which the light sensitive member is automatically moved forsuccessive readings.

It is a still further object of the invention to provide a bore holesurvey device which is sealed against fluid pressures. l

Other objects and advantages of importance will be pointed out in thefollowing description. y

The invention may be best understood by reference to theaccompanying'drawings in which:

Fig. 1 is a diagrammatic View illustrating the utility of the invention.

Fig. 2 is an enlarged vertical section of the upper part of theapparatus.

Fig. 3 is a section on thesame scale as Fig. 2 showing the central partof the apparatus. y i

Fig. 4 is a section on the same scale as Figs.y 2 and 3 showing thelower part of the apparatus. l

Fig. 5 is a section taken on the line 5-5 of Fig. 2.

Fig. 6 is a section taken on the line 6 6 of Fig. 2.

Fig. 7 is a Asection taken on the line 7-7 CTI Fig. 9 is a section takenon the line 9-9 of Fig. 3.

Fig'. 10 is a section taken on the line 10-10 ot Fig. 9.

Fig'. 11 is a section taken on the line 11-11 of Fig. 4.

Fig. 12 is an enlarged detail ot' the lower end of the pendulum of theinvention.

Fig. 13 is a section taken on the line 13-13 ot Fig. 12.

Fig. 14 is a view of the central portion of the apparatus showing theposition of the pendulum when the apparatus is in a portion ot a borehole which is not vertical.

Fig. 15 is a section taken on the line 15-15 ot Fig. 14.

Figs. 16 and 17 are diagrams showing the manner in which the amount anddirection of deviation is calculated.

Fig. 18 is a view of a light recording member showing two readings takenin the apparatus ot my invention.

Referring to the drawings in detail, particularly to Fig. 1, the numeral2O represents a well in which the bore hole survey device 21 of myinvention is lowered by means of a cable 22. The cable 22 is attached tothe survey device by means of a Coupling member 23, as shown in Fig. 2.The cable 22 carries a pair of conductors 24 and 25, and the outersheath 26 of the cable serves as a ground conductor. Referringparticularly to Figs. 2, 3 and 4, the survey device 21 has an outershell 28 to the upper end of which an upper head 29 is threadedlysecured and to the lower end of which a lower head 30 is tln'eadedlysecured. Carried inside the upper end of the shell 28 and the upper head29 is an upper block 31. Extending from the upper block 31 is a stem 32to which the coupling member 23 is threadedly connected at- The upperblock 31 provides a shoulder 34 and the upper end ot the shell 28provides a shoulder 35. Placed between the shoulders 34 and 35 is agasket member 36. The upper block 31 is forced downward so as tocompress the gasket member 36 and torm a tight seal by means of screws37 which are carried hy the upper head 29. As shown in Fig. 3, the lowerhead 30 in the lower end of the shell 28 eucloses a lower block 39. rlhelower block 39 has an annular shoulder 40. and the lower end ot theshell 28 has an annular shoulder 41. Adapted to be compressed betweenthese shoulders is a gasket member 42. Threaded into the lower end otthe lower head 3() are screws 43 which are adapted to force the lowerblock 39 upward so as to compress the gasket member 42 and torm afluid-tight seal at this point.

Depending' from the lower head 30 is a centralizing member `rI4. Thiseentralizing member 44 has a body portion 45 which is secured to thelower head, as shown, this body portion 45 carrying spring arms 46 whichare adapted to engage the walls o't the casing 47 of the well 20. Thisstructure centralizes the lower end of the survey device. The upper endof the survey device is centralized by an upper centralizing means shownat 48 in Fig. 1. This upper centralizing means is carried above the stem32, having spring arms 50 which engage the inner walls of the wellcasing 47.

As illustrated best in Figs. 2, 5 and 6, the lower part of the upperblock 31 has an up per bearing block 53 secured thereto by suitable pins54. Attached to the upper bearing block 53 is a housing 54 to the lowerend of which a lower bearing plate formed of insulation material isattached. This construction provides a gyroscope housing for theinvention. The upper bearing block 53 Carries an upper bearing 56 andthe lower bearing block carries a lower bearing 58. Carried by thebearings 56 and 58 is a frame 59 which is free to rotate. The frame 59has an upper trunnion 60 which engages the upper bearing 56 and a lowertrunnion 61 which engages the lower bearing 58. In order that there beno vertical play between the frame v59 and the bearings, the uppertrunnion 56 is provided withan adjustment nut 62 which may be .screweddownward so as to increase the distance between the trunnions, thuseliminating any play which may exist. The frame 59, as shown in Fig. 5,carries pivots 64 which pivotally support a yoke 65. r1`he yoke 65carries a shaft 66 on which a stator 67 is secured. The'shaft 66 carriesbearings 68 on which a rotor 69 is free to rotate. The yoke 65, thestator 67, the frame 59, and the rotor 69 comprise the gyroscope of theinvention. The details of this construction do not comprise a part ofthis invention and are therefore not illustrated in detail in thisapplication.

The gyroscope is connected in an electricitvr supplycircuitas follows:EXtendingt-hrough the upper block 31 and the stem 32 is aconductor rod70 which is insulated 'from the other metal parts. asshown. The upperend ot this conductor rod 70 is connected to the conductor 24 whichextends through the cable 22. rl`he lower end of the conductor rod 70 isprovided with a suitable checking means 71 which is Huid-tight toprevent fiuids from the well from reaching the interior of theapparatus. The lower end ot this conductor rod 70 is connected by a wire72 to a bushing 73 which is carried by an insulation plate 74. thisinsulation plate 74 being supoorted by the upper hearing block 53.lxtending through the upper trunnion 60 oi' the trame 59 is a conductorrod 75, this conductor rod 75 being in electrical contact with thebushing 73 by a. spring contact member 76. The eouductor rod 75 isinsulated from the uppe,` trunnion 60, as shown. The conductor rod 75 isconnected by a conductor 77 to one of the pivots 64, as shown in Figs. 2and 5, which is insulated from the frame 59. A bearing 79 which isvengaged by this insulated pivot is insulated from the yoke 65, as shown.Connected to this bearing 79 is a wire 8O which extends to one side of-the winding of the stator 67. The other side of the stator winding isgrounded to the yoke 65, as shown. The yoke 65 is in electrical Contactwith the upper bearing 56 and is consequently in electrical contact withthe sheath 26 of the cable 22. At the surface of the ground, as shown inFig. 1, the conductor 24 is connected to a suitable generator 80 whichsupplies current for operating the gyroscope. The current source 80 isin turn connected by a conductor 81 to the sheath 26, thus completingthe electric circuit.

It is essential that the gyr'oscope be very carefully balanced. In Viewof the fact that some of the material is cut away and replaced byinsulation material which is lighter it is necessary to provide abalancing means. In the invention, as shown in Fig. 2, I show abalancing means comprising a cross-shaft 83 which is threaded and onwhich adjustable weights 84 are placed. These weights may beadjusted tovarious positions on the shaft 83. The lower trunnion 61 has a plate 90formed on the lower end thereof below the lower bearing plate 55. Thisplate 90 comprises apart of a pendulum supportingsmeans of theinvention. This pendulum supporting means includes a tube 91 which issecured to the plate 90 and depends therefrom. The lower end of the tube91 supports a yoke 92 by pivots 93. Supported from the yoke 92 by pivots94, as shown in Fig. 7, is a pendulum 95 of the invention which isillustrated in Figs. 3, 7, 12, 13 and 14. The pendulum 95 has anvuppermember'96 which is engaged by the pivots 94 and which supports anillumination source in the form of a lamp 97. Extending downward fromthe part 96 is a shell or housing 98 at the lower end of which a mirrorsupporting vmember 99 is attached. The mirror supporting member 99 isshown in detail in Figs. 12 and 13 The extreme lower end thereof is inthe form of a tubular projection 100.-,which supports a block 101. Thisblock 101 carries deiecting means in the, form of mirrors, there being anorth mirror 103, an east mirror 104, a south mirror 105,` and a westmirror 106. These mirrors 103 to 106 inclusive are'disposed yon planesat fortyfive degrees to thecentral axis A-A of the pendulum 95. A lrayof light passing parallel to the axis A+A will be deflected by the.mirrors at right angles thereto. Adjacent to each mirror is an openingf107 in the tubular pro] ection 100 through which the reliected lightrays may pass. The north mirror 103 is distinguished from-the othervmirrors by having a central opaque'portion 109 which will not reliectlight. Su )ported in the shell 98 below the light source 9 is a lens 111which focuses the light rays from the light source.

' to the lower end of the conductor rod 112 by means of a conductor 115.The bushing 114 has a conductor 116 connected thereto, this conductor116 extending downwardly tothe lower side of the lower bearing plate 55.Secured to the lower face of the lower bearing plate 55 is a contactring 118 to which the conductor 116 is connected. Carried by the lowerbearing plate 55 is a resistance coil 120 which is provided for thepurpose of reducing the current. f The lower bearing plate 55 has ametallic member 121 connected thereto by screws 122. The metallic member121 is electrically connected to the resistance coil 120 by means of aconductor 123, asfshown in Fig. 2. The metallic member 121 of the lowerbearing plate 55 is in electrical contact with the lower bearing 58,this lower bearing 58 being insulated from the lower trunnions 61 of theframe 59 and the plate 90.

Connected to the bearing 58l and the lamp 97 Y is a conductor 125. Thelamp 97 is in electrical contact with the metallic parts of the pendulumand pendulum support, and the pendulum support is in electricalv Contactwith the frame 59. l In/Kthis manner one side of this circuit isconnected to the sheath 26.

Referring to Fig. 1, the conductor 25 is'con-V dulum 95 and the pendulumsupport means,'

this conductor tube 135 being insulated from the shell 28 by aninsulation wall 136. As shown in Fig. 2. the conductor tube 135 hascontact lingers 137 whichengage the contact ring 118, thus connectingthe conductor tube infthe electric circuit which includes the conductor116. Referring to Fig. 3, at the lower end of the survey device is afilm lowering control mechanism 139. This mechanism in. cludes a plate140 made of insulation material and threadedly secured to the lowerblock 30. Attached to the plate 140 is a housing 142 which encloses themechanism. An eleccheck of the distance of tromagnet 1&3 having anassociated armature 144 is supported by the plate 1110. Thiselectromagnct 141-3 is connected by a conductor to the conductor tube135. The electromagnet 1-13 is also connected by a conductor 146 to aplate 147 attached to the lower part of the insulation plate 140. Inthis manner the conductor 1.46 is grounded to the apparatus iand is inelectrical contactv with the sheath Q6 ot the cable 22. It will be seenthat the electromagnet is connected in the same main circuit with thelamp 97 and is energized whenever the switch 129 is closed. As shownbest in Fig. 10, the housing 142 has a pair of webs 148 which carries ashaft 149 on which a drum 150 is rotatable. The drum 150 has aconcentric gear 151 which is in mesh with a gear 159l carriedl by ashaft 153. Mounted on one end of the shaft 153 is an cscapement wheel155 having projections in the form of pins 156. Adapted to control themovement ot the escapement wheel 155 is an escapement arm 157 havingpawls 158. The escapement arm 157 has a lever 160 which is connected tothe armature 1.4i., as shown. .1 tension spring 161 is connected to theescapement arm 157 for resiliently retaining it in the position shown inthe drawings. TWhen the electromagnet is energized, the escapement armis moved so that the upper pawl 158 is disengaged from one of the pins156 and the lower pawl is moved into the path of the pins. This willallow the escapcment wheel 155 to move a portion of a revolution. ltshould bc understood that the operation of this escapen'icnt device isthe same as the escapement in any clocl: mechanism. TWrapped on the drum150 is a flexible member in the torni ot a cord 163. This cord 163extends upward as shown in 3, and over a sheave 165 supported at theupper end of a vertical column 166. The upper end 167 of the cord 163 isconnected to a lower head 168 of a light sensitive member carrier 170.Proiect-ing up-l ward from the head 168 is a tube171 which larries alight sensitive member 172. This light sensitive member is tubular inform and surrounds the mirrors 103 to 106 inclusive. Tt- )Drill be seenthat the weight of the light sensitive member carrier 170 tends tounwind the cord 163 from the drum 150. This places a rotative force onthe escapement wheel 155 and whenever the escapemcnt arm 157 isoperated, these parts will rotate, allowing the cord to unwind andlallowing the light sensitive member carrier 170 to lower a shortdistance. This is provided so that successive readings will be spaced ashort distance on the light sensitive member 172.

Tn the operation of the invention the survey device Q1 is lowered intothe well, as shown in Fig. 1. In lowering the survey device the operatorwill keep an accurate low the surface oit the ground. In other thesurvey device be-V words, he must know the depth at which eachsuccessive reading is taken. In setting up the apparatus, the recordingmechanism is disposed so that the mirror 109 points to the north, or, itdesired, it -may be arranged to point in any direction, but thisdirection must be known to the operator. The gyroscope maintains theazimuth ot the recording mechanism. During the lowering ot the dcvicethrough the well the recording mechanism will not rotate with the otherparts ot the apparatus because ot the gyroscope. A relative movementbetween these parts is provided for by the upper and lower bearings 56and 58. lt will, therefore, be seen that cvcn though the shell ot thesurvey apparatus rotates, the recording mechanism will be Imaintained inits original azimut-h. The survey device is lowered to a point where itis desired to malte a reading. At this time the switch 120 is closedwhich closes the circuits to the lamp 07 and tothe electromagnet 1&3.The lamp 07 projects light rays through the lens 111 onto the :tourmirrors 103 to 106 inclusive. These mirrors separate the .shaft of lightand cast tour separate images onto the light sensitive member 173. Theenergization ot the electromagnet lll operates the til-m loweringmechanism, and the iilm 173 will be lowered a short distance. Thislowering is very sudden and will not have any detrimental elllect on theimages cast because it taires a .tew seconds for the image to be formed.mConsequently, the light rays are focused for a period of time on thelight sensitive member immediately ai'ter it has been lowered. The quickmovement ot the light sensitive member during the projection ot thelight rays may cause a slight streak. but this is not at all detrimentalto the reading.

Tn Fig. 18 T show a light sensitive member in 'fiat position which has'two recordsI thereon. The upper record has been recorded when theapparatus was in vertical position. Tt will be seen that the dots 181.are equally spaced. The reading 182 was taken when the survey apparatuswas in the position shown in Figs. 1-1- and 15. Tt will be seen that thefour dots 183 are unequally spaced. The reason for thiswill beunderstood by referring to `Fig. 15. The pendulum 95 at all timesretains a vertical position. lVhen the remainder ot the apparatus movesout of vertical position the mirrors 103 to 106 move nearer to one sideot the apparatus as is shown clearly in Fig. 15. The light rays arealways directed horizontally at ninety degrees to each other, and inview oit the fact lthat the light rays 185 from the mirrors 103 and 104are shorter than the light rays 186 from the mirrors 105 and 106, thedots 183 yformed on the ilm by the rays 185 will be closer together. y j

Referring to Figs. 16 and 17, the method llO by which the direction andamount of inclination oiC the Well at a certain point is computed willbe explained. llig. l gives an example ot computing the direction andamount of inclination when the pendulum is in the position shown inFigs. lll and l5. Referring to this ligure the values are as tollows:

L:lEi-l`eetive length ci pendulum l?, :Radius of light sensitive memberN, E, S, and `W:Four dots 183 made on film D-D :Vertical plane oi tiltC:Angle between plane oi tilt and north direction A Northerly componentangle :c1 Circumierence subtended by angle A B :Easterly component angley1 Circumierence Subt-end ed by angle B Angle A: l-g degrees l. Angle B:l {8F-0 degrees :R sin A gh-:R sin B l Angle of inclination-sin L sin LO tan1 E?.

In the diagrams the cardinal points 189 may be found by locatingone-half the circumferential distance between alternate dots 183, thatis l/V-E N-S 2 and 2 'When these cardinal points are located, thecircumferential distances wl and g/l may be Which to compute the angleof inclination scaled oli, thus giving the complete data by and also theangle Gfthese two being the important informations from which thetangles or inclination and directions of inclination ot the Wellthroughout its length maybe computed.

In the foregoing description I have illustrated but a preferred form ofthe invention. `It should be understood that various modifications maybe made Without departing from the spirit and scope of the invention andit is my intention to cover all mechanical equivalents.

Certain apparatus disclosed in this application is specifically claimedin a co-pending application tiled August 8, 1927, Serial No. 211,416.

I claim as my invention:

l. In a bore hole survey device, the combination of: a shell; blocksadapted to be secured to opposite ends of said shell; a gyroscopemounted on one of said blocks and removable therewith; a controlmechanism mounted on the other ot said blocks and removable therewith; alight-sensitive member adapted to be advanced by said control mech- Yanism; and means carried by said gyroscope for exposing saidlight-sensitive member as a "function or" the position oi? said surveydevice.

2. In a bore hole survey device, the combination of: a shell; blocksadapted to be secured to opposite ends of said shell; a pendulumsuspended in said shell belovvthe upper of said blocks in a manner to beremovable therevith; means for retaining a light-sensitive member insaid shell, said member being adapted to record successive positions or"the tree end of said pendulum; and a control mechanism secured to thelower of said blocks `tor controlling the relative movement between saidpendulum and said light-sensitive member between successive exposures.

8. In a bore hol-e survey device including means 'for exposing aJractional portion of a light-sensitive member as a function of theinclination of said survey device, the combination of: a shell; acarrier slidably retained in said shell and retaining saidlightsensitive member; an escapement controlling the movement of saidcarrier and its associated light-sensitive member; and means forcontrolling said escapement. v 4. In a bore hole survey device includingmeans for exposing a fractional portion ot a light-sensitive member as aJfunction of the inclination of said survey device, the combination'of:a shell; a carrier slidably retained in said shell and retaining saidlightsensitive member; a sheave inside said shell; an escapementcontrolled driven means below said sheave and including an cscapement; aflexible member operatively connecting said carrier and saidescapement-controlled means and extending over said sheave Whereby theWeight of said carrier tends to operate said escape]nent-controlledmeans; and control means for said cscapement.

5. A bore hole survey device comprising: a supporting structure adaptedto be lowered into a Well; a pendulum supported in said supportingstructure; means whereby said pendulum is maintained at a fixed azimuthindependent of said supporting' structure; a recording mediumcylindrically arranged in said supporting structure independent ot saidpendulum and said means; and mechanism for recording indicia on saidrecording medium as a function of the relative positions of saidpendulum and said recording` medium.

In testimony whereof, Iliave hereunto set my hand at Los Angeles,California, this 27 th day oit July,1927.

i l/VALTGN E. GILBERT.

f Certiicate of Correction Patent No. l9l2f'58.

June G, i933. TALTON E. GILBERT.

d that error appears in the uir'lng correction as fc Hows It is herebycertifie printed specication of the abovenumhel'ed patent req Page 5,line 27, 111 the Angle B read l, and that the Saud Letters Patentcorrection therein that t ffices Signed and sealed this 11th day ofJu1y,A. D. 1933.

[SEAL] formula for shoud he read with this he same may conform to therecord of the ease in the Patent M. J. MOORE, cz'fzg @ammissanef 0fPatents.

